Coalminers’ pneumoconiosis and lung function, and exposure to dust of variable quartz content.

This thesis describes the design and execution of a study in which existing radiographs for men at a colliery in Midlothian were subjected to intensive re-examination, with the object of relating any evidence of radiographic abmormalities to data already held on the individual mens’ exposures to respirable airborne dust in the coal mines, and on lung function and smoking habits. All available radiographs for over 1400 men who had attended medical surveys in 1970, 1974 and 1978 were collected, along with some taken by the NCB’s Medical Service in 1980; these were classified for pneumoconiotic abnormalities according to the ILO (1980) scheme. Analyses confirmed that appearances of small pneumoconiotic shadows of profusion at least 1/0 on the ILO (1980) scale were associated most strongly with the estimates of individuals’ exposures to respirable coal mine dusts from before the 1970 to after the 1974 surveys, and particularly with estimates of exposures to the quartz components of these dusts. There was no evidence that the men’s smoking habits were an important modifying factor in this association. There was also no evidence of a relationship between apparently dust-related lung function effects observed between the 1974 and 1978 surveys and the radiographic abnormalities ascribed to quartz exposures.